NatronNa2CO3 · 10H2O

Natron is relatively rare at MSH. Once exposed to air, it alters very rapidly to thermonatrite.

PHYSICAL CHARACTERISTICS:

Color is usually colorless.Luster is dull.Diaphaneity is transparent. Crystal System is monoclinic; Cc.Crystal Habits include crystalline masses to 4cm, rarely anhedral crystals.Cleavage {001} is distinct and {010} is imperfect.Fracture is conchoidal.Hardness is 1.Specific Gravity is approximately 1.5 g/cm3.Streak is white.Associated Minerals include ussingite, villiaumite and most
of the species found in sodalite xenoliths.Distinguishing Features: Color and alteration to thermonatrite.Origin: Named in antiquity from the Hebraic neter, alkaline salts, referring to its sodium content.